JPH0384867A - Fuel cell - Google Patents

Abstract

PURPOSE:To realize a long service life of a cell by applying an anticorrosive process to one side surface, forming numerous bending process members and holes so as to form gas passages at the same time, and forming them into a current collector. CONSTITUTION:Cuttings 11 are provided to numerous positions of a plate 10a where an anticorrosive process is applied, and, while tongue pieces 12 are bent to one side to form gas passages 15, a current collector 10 composed to furnish numerous holes 13 is laminated contacting to electrodes 2 and 3. As a result, by the uneven structure formed by bending the tongue pieces 12, the gas passages 15 are formed, a corrugate plate in a separator 4 can be omitted, and only one separator plate 14 is necessary to use as a separator 4. Consequently, the manufacturing cost is can be reduced, a long service life of the cell is realized, and the masking process is made unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to fuel cells used in the energy sector for directly converting the chemical energy of fuel into electrical energy, and in particular to molten carbonate fuel cells.

[Prior Art] A conventional molten carbonate fuel cell, as shown schematically in FIG. By sandwiching the oxygen electrode (oxygen electrode) 2 and the anode (fuel electrode) 3 from both sides, and supplying the oxidizing gas OG to the cathode 2 side and the fuel gas FG to the anode 3 side, the reaction on the cathode 2 side The obtained carbonate ions CO3°- are guided through the electrolyte plate 1 to the 7 node 3, and react with the fuel gas on the anode 3 side, causing the cathode 2 and the anode 3 to react.
One cell C is configured to generate electricity by the potential difference generated between the two cells, and each cell is laminated in multiple layers with a separator 4 in between to form a stack.

Separator 4 used in such a molten carbonate fuel cell
It has been proposed that corrugated plates 6 are stacked on both sides of the center plate 5, and gas passages are formed by the unevenness of the corrugated plates 6. If the pitch is wide, prevent deformation of the electrodes and -
In order to ensure various contact, a punch plate 7 is used in combination on the outside of the corrugated plate 6, and the punch plate γ
is used as the current collector.

[Problems to be Solved by the Invention] However, in molten carbonate fuel cells, the operating temperature is as high as 600 to 700°C, and the separator is exposed to both oxidizing and reducing atmospheres in molten carbonate, which is highly corrosive. Because of this, the separator is prone to corrosion, and as the separator corrosion progresses, lithium in the molten carbonate is consumed and at the same time contact resistance increases, reducing the battery life. Therefore, it is necessary for the separator to have anti-corrosion properties, but in conventional fuel cells, the base material of the separator itself is made of a material that has anti-corrosion properties, and no special anti-corrosion treatment is applied.

SUMMARY OF THE INVENTION Therefore, the present invention aims to provide a fuel cell in which a current collector is formed by applying anti-corrosion treatment on one side and forming a large number of bent parts and holes to simultaneously form gas passages. be.

[Means for Solving the Problems] In order to solve the above problems, the present invention sandwiches an electrolyte plate between both electrodes, a cathode and an anode, and supplies oxidizing gas to the cathode side and fuel gas to the anode side. In a fuel cell in which cells are stacked in multiple layers via separators, each plate is coated with anti-corrosion treatment on one side, and U-shaped notches are provided at multiple locations. A current collector is constructed by bending the tongue piece of each cut portion toward one side, and the one side of the current collector is brought into contact with a separator plate, and the tongue is folded between the separator plate and the current collector. It has a configuration in which a gas passage is formed by a curved tongue piece.

In addition, methods for applying anti-corrosion treatment to the plate include a method of coating one side with aluminum or the like, or a method of diffusion bonding one plate as a base material and aluminum or the like to form clad steel.

[Function 1] A large number of holes are simultaneously formed by cutting tongues formed in multiple places on one anti-corrosion plate and bending them to one side, so it functions as a punch plate.
Further, a gas passage is formed by bringing the bent tongue piece into contact with the separator plate. This allows the conventional corrugated board to be omitted. In addition, the anti-corrosion treatment is 1
Since this is done when a sheet is being coated, the masking step during coating can be omitted compared to when anti-corrosion treatment is performed after processing.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention, in which one plate 10a as a base material has an anti-corrosion treatment layer 10b coated with aluminum or the like on one side, and A large number of U-shaped cut portions 11 are provided in a plan view, and the tongue piece 12 formed by the cut portions 11 is bent at an angle of approximately 90 degrees toward one side on which the anti-corrosion treatment layer 10b is located. The current collector 10 is constructed by forming unevenness for forming gas passages and forming a large number of holes 13.

When the cells C are stacked such that the electrolyte plate 1 is sandwiched between the cathode 2 and the anode 3 from both sides to form a stack, and each cell C is partitioned through a separator, the current collector 10 having the above structure is used. anti-corrosion treatment layer 10b
The bent tongue pieces 12 are made to face each other so that the opposite side thereof is in contact with each electrode of the cathode 2 and anode 3, and between the bent tongue pieces 12 of both current collectors 10,
A separator plate 14 is interposed as a center plate of a conventional separator, and a gas passage 15 is formed between the current collector 10 and the separator plate 14 by the unevenness of the bent tongue piece 12 of both current collectors 10 between each cell C. Let it form.

The oxidizing gas OG supplied to the cathode 2 side
After being supplied to the gas passage 15 formed between the current collector 10 and the separator plate 14 that are in contact with the current collector 10 , it is led to the cathode 2 through the respective parts 13 of the current collector 10 . Similarly, the fuel gas FG guided to the anode 3 side is fed to the current collector 1 which contacts the anode 3.
After being supplied to the gas passage 15 formed between the current collector 10 and the separator plate 14, the gas is led to the anode 3 through the current collectors 13.

Carbonate ion CO3 obtained by reaction on the cathode 2 side
When - is led to the 7 node 3 side through the electrolyte plate 1, a reaction with the fuel gas takes place at the anode 3. In this reaction, electricity is caused to flow due to the potential difference generated between the cathode 2 side and the anode 3, but the current collector 10, the parts used for electricity to flow are not anti-corrosion treated, so they do not interfere with the flow of electricity, and since the anti-corrosion treatment is applied to a single plate, it is difficult to prevent corrosion after processing. The masking step during coating, such as when applying anticorrosion treatment, can be omitted.

In the fuel cell of the present invention, the current collector 10
Since anti-corrosion treatment is applied to the parts other than those used to conduct electricity, the current collector 10 is prevented from corrosion even when exposed to highly corrosive molten carbonate at high operating temperatures. As a result, the loss of lithium in the electrolyte due to corrosion can be reduced, making it possible to extend the life of the battery.

Note that the present invention is not limited to the above-described embodiments, and that, for example, the bent shape of the tongue piece 12, the shape and pitch of the hole 13, etc. may be other than those shown in the drawings;
Although the case in which anti-corrosion treatment is applied to one side of a single plate is shown, it is also possible to process clad steel in which heat-resistant steel as a base material and an aluminum ferrite layer are diffusion bonded to form a current collector. Of course, various changes can be made without departing from the gist of the invention.

[Effects of the Invention] As described above, according to the fuel cell of the present invention, the gas passages are formed by providing notches at multiple locations in one plate that has been subjected to anti-corrosion treatment and by bending the tongue piece to one side. Since the current collectors are stacked in contact with the electrodes and have a large number of holes, gas passages can be formed by the unevenness formed by bending the tongues. Therefore, the corrugated plate in the conventional separator consisting of a center plate and a corrugated plate can be omitted, and the separator only has one
Only one separator plate is required, which reduces production costs, reduces the loss of electrolyte due to corrosion, and extends battery life.Also, since it is processed after anti-corrosion treatment, It is possible to omit the masking step required for corrosion prevention after processing, and furthermore, since it is made of a single plate, it can exhibit excellent effects such as being able to reduce contact resistance.

[Brief explanation of drawings]

FIG. 1 is a cutaway side view of a portion showing an embodiment of the fuel cell of the present invention, FIG. 2 is a perspective view of a current collector in the fuel cell of the present invention, and FIG. 3 is a cutaway view of an example of a conventional fuel cell. It is a front view. DESCRIPTION OF SYMBOLS 1... Electrolyte plate, 2... Cathode, 3... Anode, 4... Separator, 10... Current collector, 10a... Plate, 10b... Anticorrosion treatment layer,
11... Notch portion, 12... Tongue piece, 13... Hole,
14...Separator plate, 15...Gas passage,
OG...oxidizing gas, FG...fuel gas.

Claims (1)

[Claims] (1) A current collector is constructed by providing notches at multiple locations on a single plate that has been treated with anti-corrosion treatment, and bending the tongues of the notches toward one side that has been treated with anti-corrosion treatment to form uneven portions. The electrolyte plate is sandwiched between the cathode and anode electrodes so that oxidizing gas is supplied to the cathode side and fuel gas is supplied to the anode side. 1. A fuel cell characterized in that one side of the bent tongues are in contact with each other, and a separator plate is interposed between the bent tongues of each current collector between cells.